WHAT IS IIFYM/FLEXIBLE DIETING?

"Flexible dieting" and "If It Fits Your Macros," or IIFYM, are two terms that both refer to basing your food intake on macronutrient targets.

With this approach you can eat anything you want, as long as it fits your macronutrient targets. No food group is off limits. You have the flexibility to eat baked chicken with rice one day and fried chicken the next—if it fits your macros, it's fair game.

WHAT ARE MACROS, AND WHY DO THEY MATTER?

Macronutrients, or macros, are the building blocks that make up all the food we eat: carbohydrates, fats, and proteins. Each has distinct roles in the body. To stay healthy and crush your body-composition goals, you need to eat the right amount of each macro.

CARBOHYDRATES

Carbohydrates are the body's preferred energy source. They make you move! Not getting enough of these "partiers of the body" can leave you lethargic. Too much will spike your blood sugar and send your hunger through the roof.

FATS

Fats also provide energy, and you need this macronutrient to help your immune system function, control your hormones, and power your nervous system (your brain is 60 percent fat).[1] But if you eat more fat than you need, you'll store it until you can use it.

PROTEIN

If there was a popularity contest for macronutrients, protein would win. Everybody knows you need lots of it to recover from workouts and build muscle, and protein suppresses your appetite to boot. But if you get too many of your calories from protein at the expense of other macros, you can become sluggish, since it isn't a very good energy source.

HOW DO YOU COUNT MACROS?

With flexible dieting, you count the grams of each macronutrient in the food you eat, rather than a total number of calories. The calculator on this page will provide an optimal macronutrient ratio based on your goals—fat loss, muscle gains, or maintenance.

Don't worry too much about calories; if you're staying close to your macro targets, your calories will fall in line. More than just the number of calories, it's the types of calories that alter your body composition.

WHY COUNTING MACROS WORKS

The big appeal of counting macros is that, since no food group is off limits, it feels much less restrictive and more sustainable than other diet approaches, which might, for example, ban carbs or demonize processed food.

Forbidding certain foods tends to just make you want them more, and omitting entire food groups can set you up for dangerous deficiencies and lead to cravings. The restrictive aspect is what stresses people out and creates the need for a cheat day, which can turn into a binge and send you back to square one.[2]

With IIFYM, the idea is that you can cheat all the time without derailing your program, as long as you keep your macros in check. If you're having a stressful week and you want to get all your macros from toaster waffles and protein pudding, nobody's stopping you.

IIFYM makes sure your body is getting all the macronutrients it needs to function properly, build muscle, and have enough energy. Even though there is flexibility in how you "spend" your macros, you can't blow all your calories on french fries and miss out on protein the way you could if you were just counting calories.

MACROS AND MICROS

The one thing IIFYM doesn't account for is micronutrients. These are the vitamins, minerals, and fiber that come along with the macros and help our bodies perform at their best.

For the most part, getting your macros from whole plant foods and animal proteins will automatically optimize your micronutrient intake. If, on the other hand, you're eating a lot of stuff like protein bars and gummy bears (which are scientifically proven to make you swole), also consider eating a vegetable once in a while.[3] Leafy greens are loaded with micros and extremely low in macros, so they're basically "free."

CHOOSE YOUR OWN MACRO ADVENTURE

The great thing about IIFYM or flexible dieting is that it really is flexible; you can customize it to work best for your individual body. Even though the macronutrient ratios presented by the calculator are a healthy and effective starting point for just about anyone, people vary in their tolerance of different macros: Some individuals do better with lots of carbs while others thrive on more fat.

You can start figuring out what combination your body prefers by tinkering with your macro ratios while keeping your calorie level stable. You might find this is all it takes to start feeling more energized and seeing better results—without the need to starve yourself.

Always consult with a qualified healthcare professional prior to beginning any diet or exercise program or taking any dietary supplement. The content on our website is for informational and educational purposes only and is not intended as medical advice or to replace a relationship with a qualified healthcare professional.